<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); 
				$post_custom = get_post_meta($post->ID,'reedwan_page_sidebar',true);
			endwhile; endif; 
			
			if (!empty($post_custom)){
				dynamic_sidebar($post_custom);
			} else {
				dynamic_sidebar(get_sidebar_name());
			}	 
?>